Just recently there was a very good interview on NPR about this magnificent phenomenon. Tom Ashbrook interviewed I strongly recommend that you listen to this podcast. LINK

Guests on the show were:

“Justin Kasper, astrophysicist in the Solar and Stellar X-Ray Group in the High Energy Astrophysics Division of the Harvard-Smithsonian Center for Astrophysics. His latest project is leading the Solar Wind Electrons Alphas And Protons (SWEAP) investigation on the Solar Probe Plus spacecraft.